


Grown Up

by Anonymous



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Blood, Crying, Dark Sylvain Jose Gautier, Dead Dove: Do Not Eat, Explicit Sexual Content, Extremely Dubious Consent, F/M, First Kiss, First Time, Loss of Virginity, Lysithea is 15, Manipulation, Oral Sex, Painful Sex, Plot What Plot/Porn Without Plot, Sexual Coercion, Shameless Smut, Sylvain is 19/20, Tutoring, Underage Sex, Vaginal Fingering, Vaginal Sex, no beta we die like Glenn
Language: English
Status: In-Progress
Published: 2021-02-23
Updated: 2021-02-23
Packaged: 2021-03-13 08:28:43
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,876
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29648565
Author URL: https://archiveofourown.org/
Summary: “I’m not a little kid,” she tells him petulantly.He smirks. “Oh, yeah? You’re what…? Twelve?”“I’m fifteen, thank you very much. Basically an adult.” She crosses her arms. “And clearly much more mature than you are.”_____Lysithea tutors Sylvain. He ends up doing most of the teaching.Read the tags.
Relationships: Lysithea von Ordelia/Sylvain Jose Gautier
Comments: 6
Kudos: 13
Collections: Anonymous





	Grown Up

**Author's Note:**

> I love Sylvain, but I can't help but write him as an irredeemably horrible person sometimes. I got this brainworm of Sylvain manipulating Lysithea into having sex with him, and it wouldn't die so I had to write it.
> 
> Warnings for sexual coersion, manipulation, dubious consent, and sex between an adult and a minor. You've been warned.

Lysithea stops in front of the door, lets a sigh fall from her lips as she double-checks the books tucked under her arm to make sure she hasn’t forgotten anything. Of all the ways she could be spending her Saturday evening… For a moment, she kind of regrets agreeing to the professor’s request that she help tutor her classmate in Reason after he spectacularly failed a recent exam.

Maybe she’ll treat herself to some tasty desserts in the dining hall afterward, as a reward…

No, it’s no time to get distracted by sweets. With a shake of her head, she knocks on the door. There’s shuffling beyond, just for a moment, before it opens wide. Sylvain grins down at her, leans casually against the door frame with his arms crossed over his broad chest. It’s frustrating for reasons she can’t quite put her finger on to see just how much taller he is than her when they’re face to face like this. She doesn’t even quite come up to his shoulder. It’s almost as bad as standing next to Claude and Lorenz and Raphael, who all basically dwarf her…

“Lysithea,” he greets warmly, grinning a perfectly practiced grin. She opens her mouth to say something, but is distracted by the sudden realization that the top several buttons of his shirt are undone, revealing an immodest amount of his chest. She can feel her cheeks heat. “You alright?” The honey-coated concern in his voice is just as fake as his smile.

“I’m fine,” she huffs, forcing her eyes upward and holding her chin high. “May I come in?”

“Of course.” He steps to the side, ushering her in with a small, gentlemanly bow of his head, amusement sparkling in his honey-brown eyes. “I suppose I should thank you for agreeing to tutor me,” he muses as she steps into the center of the room, not so subtly taking it in. It’s… cleaner than she might have imagined. On the occasions she’s tutored Raphael or Caspar, she’d been dismayed – though unsurprised – to see the absolute mess their rooms were in. Sylvain’s room seems almost compulsively cleaned, everything perfectly tidy and in place. There are a surprising amount of books stacked neatly on the desk, each with bookmarks marking spots varying ways through them.

“Don’t mention it,” she dismisses.

“Why don’t you have a seat?” he offers, gesturing to one of the chairs by the desk. “The sooner we get this started, the sooner we can both get back to our evenings, right?”

“Right.” She crosses the room, sinks down into the chair. Sylvain takes the seat next to her. This close, she can smell whatever cologne he’s wearing, something deep and sharp, likely expensive. It’s almost overpowering.

Doing her best to push it from her mind, she sets one of her books in front of him and flips to a page she’s marked. “I thought we might start here,” she explains, “since the professor mentioned this is something you seemed to struggle with on the exam.”

“You’re the boss.”

She begins the lecture she’d meticulously planned in her mind, referring back to the book as she goes over the concepts discussed. Sylvain seems to follow along easy enough, answering her questions and restating the main ideas with ease. The longer they talk, the more confused she becomes. It doesn’t seem like he’s struggling to understand at all…

No, if she didn’t know any better, she would think he _already knew_ everything they were going over.

Growing suspicious, she subtly moves on to more difficult topics, things that would have been way out of the scope of his knowledge if he really didn’t know the basics. And, just as before, he follows without difficulty.

She glares at him, snapping the book shut. “You already know all of this,” she accuses.

He rubs the back of his neck, grinning lopsidedly. “Yeah, I do.”

“If you already know it, why am I here? Did you… fail your test on purpose or something?”

“Not exactly,” he laughs. “I got pretty trashed the night before and had a hangover during the exam. The professor insisted I see a tutor.”

She stands in a huff. “Well, thank you very much for wasting my time.” Frustrated, she begins hastily gathering her books when Sylvain grabs her arm to stop her. It’s almost comically large, encircling her wrist with ease.

“Hey, I’m sorry,” he says with what she supposes is supposed to be a charming smile. “It wasn’t my idea, you know. I was just doing what the professor said. And I kind of had fun.”

She eyes him skeptically. “Fun?” she parrots dully.

“Yeah. It was fun talking to someone about complicated Reason equations for a little while, you know?” She did know, actually. Though she wouldn’t necessarily agree spending the evening with Sylvain had been _fun_. “Actually, I kind of forgot you were such a little kid for a bit, with how much you know about this stuff.”

Anger bubbles in her chest. She’s used to that kind of talk from Claude, though, so maybe she shouldn’t have been surprised. “I’m _not_ a little kid,” she tells him petulantly.

He smirks. “Oh, yeah? You’re what…? Twelve?”

“I’m fifteen, thank you very much. Basically an adult.” She crosses her arms. “And clearly much more mature than you are.”

“Ouch,” he laughs. “You wound me, Lysithea.” He leans back in his chair, regarding her for a moment with a look that reminds her of a cat eyeing a mouse. “Don’t get me wrong, you’re plenty mature for your age, but I don’t think you're as much of an adult as you like to pretend.”

“Don’t condescend me,” she huffs, hating the way her voice is starting to sound whiny. She holds her chin up, trying very hard not to let her scowl look like a pout. “What makes you such an adult, if you think you’re so much more grown up than me?”

“I’m old enough to drink, for one thing,” he muses. As if alcohol is some gold standard for maturity. “For someone who acts like they’re such a grown up, you’ve probably never even kissed a boy.”

She feels her face heat up. “I’m much more concerned with my studies than romance,” she mutters. “I don’t have time for such nonsense.”

He laughs, shaking his head. “So that’s a no. I bet you don’t even know what sex is, Miss Mature Adult.”

Her face must be bright red. She stares down at the floor. “I know what sex is,” she mumbles, more to herself than to him.

“Oh, yeah?” he teases. Out of her peripheral vision, she sees him shift in his chair, arms lounging behind his head. “Do tell.”

She bites her lip. “A man’s p-p…”

“Penis,” he supplies, and she can practically hear the smirk in his voice.

“P-penis. Goes into a woman’s…”

“Vagina.”

“Va-vagina.” She struggles for the right words, but they don’t come.

“Go on,” he urges, amused. “Penis goes in vagina. Then what?” She doesn’t answer. She’s read biology books, and has had mortifying discussions with her parents about it, but how is she supposed to put that into words? “I’ll give you a hint.” She peeks up under her lashes to see him making a crude gesture with his hands, the fingers of one hand in a circle while a finger of the other hand moves in and out.

“Don’t be so vulgar,” she spits, stamping her foot a little on the floor and regretting it immediately.

“I’m sorry, am I making you uncomfortable?” He doesn’t look very sorry. “Maybe I shouldn’t be talking about this with such a little kid. My bad.”

“I’m not a little kid!” she insists.

“It’s okay,” he assures her, the smirk still playing on his lips. “No one’s going to expect a twelve… sorry, _fifteen_ year old to understand sex. I mean, I’d already had sex by the time I was your age, but…” He shrugs like it’s nothing.

“You had?” she can’t stop herself from asking.

“Does that surprise you?” he chuckles.

“Not really.” She licks her lips, eyes darting between Sylvain’s taunting grin and the door. “If you’re such an expert, why don’t you explain it to me, then?” She doesn’t know what possesses her to say it. Maybe she thinks, somewhere deep in her subconscious, that he’ll back down once he realizes she’s no longer acting meek and embarrassed.

His grin doesn’t falter. “It’s not really something you learn by study or explanation.” His eyes are practically burning as he holds her gaze. “It’s something you learn by doing.” Her stomach feels like it’s full of knots, and her whole body feels flushed and too hot.

A boldness she can’t place the source of overcomes her. “So teach me,” she challenges.

He grins like a wolf.

She swallows hard when he stands, steps into her space. His cologne is overpowering this close, makes her head spin. Once again, she’s forced to crane her neck up to see his face. His hands wind around her waist, pulling her close to his chest. Warmth engulfs her, his body heat radiating off of him. A bulge prods against her stomach, and she’s somewhat mortified to realize it’s his penis, hard in his trousers.

Before she can fully process what’s happening, she being walked backwards until the backs of her knees bump something – the bed. Then she’s falling, supported by his thick arms. Her back hits the bed, and Sylvain is over top of her, muscular thighs straddling her hips.

“Tell me if you decide to back out,” he mutters in her ear, his breath hot against her skin. “I’ll stop, promise.” She’s not too sure she believes him, but she doesn’t have much time to question it before his lips are on hers, soft and insistent in the way they urge hers open. His tongue darts inside, coaxing hers to mingle with it. She’s not quite sure to do with her body, her hands resting awkwardly against firm biceps.

His hips grind against her as he kisses her, the friction stoking a burning warmth in her core. She can feel her smalls starting to cling to her skin with her growing arousal and is very suddenly self-conscious about it. Will he… will he think it’s gross? Will he taunt her for being dirty and… _wet_?

She feels breathless when Sylvain breaks the kiss, a thread of saliva connecting their lips for a second before it snaps. Her head is still spinning when he rolls off of her, and for a second she’s worried she did something wrong, that he’s changed his mind when he urges her off the bed.

Confusion takes worry’s place when he pushes her to her knees in front of him. His hand ruffles in her hair briefly before he starts untying the laces of his trousers.

“Have you ever seen a cock, sweetheart?” he asks, syrupy-sweet. She shakes her head slowly, lip quivering. She’s seen diagrams in medical books, but… never the real thing. He smiles as he shoves his pants down his hips, tugs down the waistband of his smalls. His penis springs free.

She swallows hard as she stares at it. It’s… big, rising out of a mess of dark red curls. Apprehension claws at her stomach at the thought that this is somehow supposed to fit _inside_ of her, and for a second she considers telling him she’s changed her mind. Stamping down her nerves, she glances up at him.

“What am I supposed to do?” She hates how small her voice sounds.

He smiles patiently, grabbing her hand in one of his own and bringing it to himself, urges her fingers to curl around it. They don’t quite touch where they circle around. Still holding on, he starts dragging her hand up and down along his length. “That’s it, baby,” he sighs, letting go of her hand to let her continue on her own. “Just like that.”

She wonders how many girls he’s said that exact thing to in the past.

His hand winds in her hair, pulling her from her musing. Her heart stutters as she realizes that he’s pulling her head closer, and she doesn’t have to ask to realize what he wants. “Wait…” He stills, cocking his head to the side and regarding her. “Is this… necessary?”

“Not _necessary_ ,” he admits, “but it feels good. And if a girl goes down on me, I always make sure I repay the favor.” She struggles for a moment to understand. In the context, to ‘go down on’ him must mean to use her mouth on him. By repaying the favor, did he intend to…? Her face feels impossibly hot at the thought. “Besides, guys love a girl who's good at giving head. Might as well practice on someone already knows you’re gonna be shit at it.” He winks. “No chance of disappointment that way.”

The challenge in his words spurs her forward, and without breaking eye contact, she licks a stripe up the underside of his penis, vindictively delighting in the way his eyelids flutter a little. She finds herself surprised at the taste, unsure what she was even expecting. Aside from the slight saltiness of his skin and the heady scent of his body, it is remarkably… tasteless. Like skin anywhere else on one's body.

The slit at the tip dribbles a clear liquid, she notices, and curiosity drives her to tentatively lap at it, her nose scrunching some at the saltiness of it. Sylvain’s hand tightens in her hair and he urges her head further down, impatient. She lets the head breach her lips.

“Watch your teeth,” he warns, though she’s not entirely sure how she’s meant to do that when his girth stretches her mouth as wide as it will go. Above her, he groans. She’s not able to take him very far in before he’s bumping against the back of her mouth. She bobs up and down slowly. “Use your hand around what won’t fit.”

She does as instructed, and if his sounds are anything to judge by, she’s not doing too bad. She finds a steady rhythm, ignoring the ache of her jaw and the soreness seeping into her knees.

Until she realizes he’s pushing her to take more. Her eyes water as his head presses toward her throat, and she gags around the intrusion. “Fuck,” he groans, forcing more of himself down her throat. She can’t breathe. And just when she feels like she’s going to puke, he pulls her head off of him completely.

She coughs and sputters, clutching at her sore throat and glaring up at him through teary eyes. “What do you think you were doing?” she rasps.

“Sorry,” he laughs, ruffling her hear again and pulling her up off the floor. She yelps as she’s yanked into his lap. “Deepthroating will probably be easier after you hit a growth spurt.” His hands start to rove her body, and she finds all of the things she wants to yell at him dissipating from her tongue. “Overall, not bad. Kinda toothy, but hey, practice makes perfect, right?”

She gasps when he pinches a nipple through her shirt. “I’ve been very rude,” he continues, voice low and husky. “What kind of gentleman takes all the pleasure for himself and leaves his lady wanting?” Expert hands grope and kneed at her breasts, and she can’t seem to remember how to speak properly. Her fingers grasp at his shirt sleeves like she might sink if she lets go.

Deft fingers unfasten the buttons of her uniform jacket, then the blouse underneath. They fall to the floor, and she shivers in the cool air of the room.

“Are you cold?” he coos, running calloused fingers lightly up and down her slender arms. “Don’t worry, I’ll keep you warm.” Her bra joins her tops on the floor. He lays her back on the bed, her head sinking into his soft pillow, enveloping her in his scent. “Aw, you’ve got such cute little tits, Lysithea.”

“Shut up,” she grumbles, voice stuttering as he tweaks one of her nipples again. She gasps when his mouth wraps around the other, his tongue lapping at it with fervor. Her hand winds into his hair, back arching off the bed. She lets her eyes fall closed, lost in the feeling.

The hand toying with her nipple wanders down, ghosting over the skin of her bare torso. She practically squeals when he gropes under her skirt, fingers skimming against her outer lips through her tights. Her legs clamp closed around his hand, and he pulls off her nipple with an obscene _pop_.

“You’re soaked,” he mutters into the crook of her neck. “So turned on by just a little bit of teasing.” She buries her face in her hands. “So hot.”

“It… it is?” she dares to ask.

“Of course. Seeing a cute girl so turned on is extremely hot.” Relief washes over her. She hears her boots clatter against the floor as he tosses them without care. His fingers hook around the waist of her skirt, and with a swift tug, she’s completely bare before him. It’s horribly unfair, considering he’s still fully dressed, aside from the way his hard length stands at attention against his stomach where it was freed from his trousers.

He settles between her thighs, raking over her body with hungry eyes. “Wow, even white down here,” he mutters, running a finger through the soft curls between her legs. His hands smooth over her thighs, pulling them wide as he lowers his head between them.

He digs in with his tongue with an enthusiasm she didn’t quite expect, and from the first touch to her womanhood, she’s seeing stars. He holds her hips firmly as he lavishes attention of her, preventing her from grinding against his tongue in search of more friction. Her head is thrown back against the pillow, close to tears when he presses a finger into her heat.

“Sylvain…” she moans, squirming some at the feeling of being penetrated. In her own exploration of her body, she’s managed only a single, slender finger. His are so much bigger than her own. He pumps it in and out of her in time with his tongue, adds a second finger.

There are tears running down her cheeks when she crests over the edge, clenching down tight around his fingers and sobbing his name. His tongue works her through it, keeps going once its passed, to the point she’s overstimulated and oversensitive. She shoves his head away with a whimper, squeezing her legs closed.

Chuckling, he crawls back up her body. Her eyes go wide as she realizes his chin is shiny with her… fluids. Smirking, he licks clean the fingers that had been inside of her before wiping his face with the back of his sleeve without care. She’s still panting, tears drying on her cheeks when he kisses her again. The taste of herself lingers on his tongue.

He manages to shrug out of his shirt without breaking the kiss, tossing it to join her clothing on the floor. The same can’t be said for his pants, which he has to shimmy down his legs with some effort before he’s naked over top of her. Her eyes drink him in, from his bare, sculpted chest, to his thighs, strong from horseback riding, to his cock still hard and bobbing.

He pulls her legs apart.

“Take a deep breath,” he murmurs once he’s settled over her, slotted between her thighs with the thick head of his cock poking against her still-sensitive core. She does, feeling the way it shudders through her.

She cries out in pain as the head breaches her, her arms instinctively clutching at his shoulders, nails digging into his skin. “It hurts,” she gasps, tears springing to her eyes again.

He kisses her neck, continuing to push in despite her pain. “You’re a girl,” he says matter-of-factly, as if that explains something. “The first time is supposed to hurt.” He doesn’t stop until he’s seated fully inside. The world is blurry through her misty eyes, her inner walls burning, even as they clench down around him. “Fuck. Virgin cunts are always so tight.”

He rolls his hips, starting a quick pace that steals her breath away. The pain is searing, and all she can do is cling onto him as he takes his pleasure. Her chest heaves with sobs as she cries, only vaguely aware of the way he bites and sucks stinging marks into the tender skin of her neck.

Slowly, the pain fades. Rather than the pleasure she hopes is supposed to replace it, it feels… kind of like nothing. _The first time is supposed to hurt_. The words buzz around in her brain. Does that imply subsequent times are meant to be better? She hopes so.

They certainly can’t be worse.

Sylvain goes tense over her, his breathing heavy and his rhythm faltering. With a grunt, he pulls out, leaving her unsatisfied and clenching around nothing. Something hot and sticky splatters between her thighs, coating her skin and globbing in the hair over her mound. She stares down at it numbly as he climbs off of her, only vaguely aware that she should probably be thankful he didn’t spend inside of her.

A damp rag lands on her stomach a moment later, pulling her back to that moment. She glances over at him where he stands by the wash basin, cleaning his softening length with another rag. It’s coming away from his skin tinged red.

With a shaking hand, she swipes the rag down between her legs. It’s spotted with blood when she examines it. Her lip trembles. She tries not to think about it as she cleans his spend out of her lower hair. And when she stands, she sees blood staining the sheet where she’d been laying.

“Don’t worry about the blood,” he offers, perhaps thinking it to be comforting. “That’s normal for virgins.” He grins, tossing a wink at her. “There's a reason it's called 'popping your cherry.'”

She stares at the floor while she redresses.

He’s pulled on his smalls and nothing else by the time she’s finished, and he steps into her space, staring softly down at her. She lets him cup her chin, lets him lean in for a soft, chaste kiss. His fingers trace over the marks he’s left on her skin, presses hard enough that they sting.

“I guess you were right,” he teases, letting his hand run down her body, cup her rear through her skirt. “You’re basically a grown up.”

“Yeah,” she mutters blandly, just wanting him to move and let her leave.

“If you want another lesson, you know where to find me.”

“Right…”

His hands leave her body and she’s free. She scoops up her book and starts for the door. He opens it for her, some gentlemanly act that they both know isn’t fooling anyone. “Thanks for the fun evening, Lysithea,” he says pleasantly as she steps out into the hall.

The door closes behind her.

Lysithea goes back to her room, her thoughts of sneaking off for sweets long passed.


End file.
